Dynamic Behavior of Submerged Cylindrical Shells Under Combined Underwater Explosion, Bubble Pulsation, and Hydrostatic Pressure

Understanding the dynamic response of cylindrical shells subjected to underwater explosion is crucial for designing safe underwater vehicles, especially in deep-water environments where the shell structures are prestressed by hydrostatic pressure. The complex combination of external loading crossing different temporal scales—from underwater explosive shock waves to bubble pulsation and hydrostatic pressure—results in a synergic damaging effect on the target structures. In this work, the dynamic responses and buckling failure mechanisms of deeply immersed (≥1300 m) cylindrical shells subjected to underwater explosion were investigated through a numerical approach using the finite element method. A convenient and reliable routine for imposing hydrostatic pressure in the Coupled Eulerian–Lagrangian model was developed and validated. Three-dimensional models, composed of spherical charges and shell targets under deep-water conditions, were established to reveal the influences of key factors, including explosion depth and explosion distance, on the failure modes. The results show that the numerical models presented in this work are capable of simulating the complex synergic effect of hydrostatic pressure, the bubble pulsation process, and shock waves on the failure mechanisms of deeply immersed cylindrical shells. This work could provide valuable guidance for the design of safer deep-water marine structures.